1. Field of the Invention
The present invention relates to a communication control device such as a computer having functions for realizing a directory service in a home network environment, a remote control of devices and a control of peripheral devices, and more particularly, to a communication control device such as a computer which may be required to control various types of devices connected to a general purpose bus.
2. Description of the Background Art
In recent years, there is a rapid trend for digitalizing electronic devices as exemplified by advances of the multi-media technology, and this trend is already noticeable in the office environment.
In terms of hardware, this trend has been materialized in forms of introduction of PCs, digitalization of OA devices and formation of networks among them. Also, in terms of software, this trend has been expanding to cover the basic functions of hosts (which are progressively light-sized and transferred to PCs), the application software such as the word-processing software, the spreadsheet software, etc., and the Internet application such as the WWW.
The similar trend can also be seen in the home environment for home use devices and related fields. Namely, even in the home environment, this trend for digitalization has been steadily progressed in forms of digitalization of AV devices (DVD, digital VTR, digital video camera, etc.), digitalization of broadcasting, and Internet access such as OCN.
This trend of technological innovations that has started from the office environment is expected to progress toward the formation of networks in future. Namely, it is expected that the technologies of various fields such as information processing, communication and broadcasting will be unified by the digitalization, and inter-mixed with each other by the formation of networks.
There are many candidates for the network technologies that provide the bases for this trend. For example, the Ethernet has overwhelming records of the actual use in the office environment and is probably the most promising candidate even for the home PC network. Also, the ATM is another serious contender because of the general consensus among the infra-structure constructors (telephone companies, CATV companies, etc.) to keep constructing the infra-structures based on this technology in view of the advantageous characteristics of the ATM such as its fast, real-time, and wide bandwidth properties.
In addition to these candidates, the network technology (bus technology) called IEEE 1394 has been attracting much attentions recently. This IEEE 1394 has several remarkable characteristics such as its fast, real-time (QOS guaranteed), and plug-and-play properties, so that there is a high expectation especially among the AV industries on the IEEE 1394 as the most promising candidate for a future scheme for inter-connecting digital AV devices. This vogue has also instigated much interests to the IEEE 1394 from the computer industries as well.
Now, the inter-mixing of various fields such as information processing, communication and broadcasting based on network formation is expected to be realized in a form of the inter-connection of the home use digital devices by these various network technologies in conjunction with the spread of the home use digital devices, depending on preferences and demands of the users, and in this way prototype digital networks will be gradually built up inside each home.
In the next phase, there will be demands for inter-connecting these digital networks together. For example, there will be a desire to inter-connect an AV device connected to the 1394 network of a guest room on the first floor with another AV device connected to the 1394 network of a private room on the second floor at the user""s home in order to realize the dubbing or the cooperative operation between these AV devices.
However, the realization of the inter-connection among digital networks within a home or between homes is associated with the following problems
(1) In the case of realizing the control of devices through networks within a home or between homes, there is no mechanism for ascertaining information such as xe2x80x9cwhich device is located at which position on the networkxe2x80x9d or xe2x80x9cwhat kind of service is being offered on the networkxe2x80x9d. Without this mechanism, the user cannot recognize the existence of a particular device/service on the network and therefore cannot operate or control the target device or receive the offered service.
(2) It is expected that parts obeying different protocols will be co-existing in the case of the inter-connection among digital networks, but there is no mechanism for conveying operation commands and the like over different protocols.
For instance, when IEEE 1394 is used, other devices such as those applicable to Internet can co-exist with devices applicable to 1394, and their protocols may not necessarily coincide. Now, in the case of realizing a remote control in such a co-existing state, that is, controlling a target device through different types of networks, it is impossible to transmit operation commands because the IEEE 1394 protocol cannot be operated in the different types of networks.
It is possible to consider the realization of remote control by providing gateways, but there is no design guideline for gateways in such a case.
As described, conventionally, even when it is desired to inter-connect digital networks within a home or between homes and carry out control of devices through networks, there has been no technique to ascertain information regarding a position of each device that exists on the network or a service that is offered on the network so that the user cannot recognize the existence of a particular device/service on the network and therefore it has been impossible for the user to carry out the operation or control of the target device or receive the offered service. In addition, when parts obeying different protocols are co-existing in the inter-connected digital networks, there has been no technique for conveying operation commands and the like over the different protocols so that it has been impossible for the user to carry out the operation or control of the target device or receive the offered service over the different protocols.
It is therefore an object of the present invention to provide a communication control device capable of realizing a uniform service providing environment without relying on a particular network.
According to one aspect of the present invention, there is provided a communication control device connected with first and second networks, comprising: a collecting unit for collecting service information of service providing devices connected with the first network, according to a first protocol depending on the first network; and a notifying unit for notifying the service information to a device connected with a second network, according to a second protocol not depending on the first network.
In this aspect of the present invention, it becomes possible to notify the service information of the service providing devices connected to the first network, independently from a protocol of a datalink of the first network, to said device connected with the second network, regardless of a datalink type of the second network. Also, it becomes possible to urge the operations with respect to these service providing devices from the second network.
In this aspect of the present invention, the second protocol may be a network layer protocol, while the first protocol may be depending on a datalink of the first network.
Also, in this aspect of the present invention, the communication control device may further comprises: a receiving unit for receiving a second protocol packet for controlling at least one of the service providing devices connected with the first network, from said device connected with the second network; and a control unit for controlling said at least one of the service providing devices specified by the second protocol packet, according to the first protocol.
In this case, it becomes possible to control a node on the first network from a node on the second network by means of the protocol conversion by the control unit, even in a case where the first network and the second network adopt protocols of different link levels so that their connection terminals can only understand protocols depending on the respective networks, for example. Namely, it becomes possible to realize the control from an arbitrary device of the second network, regardless of a datalink type of the first network, even in a case where a control target node can only understand a protocol depending on the datalink type of the first network.
Similarly, in this aspect of the present invention, the notifying unit may also notify the service information to another device connected with the first network, and the communication control device may further comprises: a receiving unit for receiving a second protocol packet for controlling at least one of the service providing devices connected with the first network, from said another device; and a control unit for controlling said at least one of the service providing devices specified by the second protocol packet, according to the first protocol.
Also, in this aspect of the present invention, the notifying unit may notify the service information to a directory agent of the second network, so as to register a service provided by one service providing device into the directory agent on behalf of said one service providing device.
In this case, it becomes possible for the directory agent to register the services provided in the datalink layer protocol (such as the AV/C protocol of the IEEE 1394, etc., for example) with respect to the directory service in the protocol (the network layer protocol such as IP, etc., for example) by which it is operated. As a result, the directory agent or the directory service can search out the services provided on the network regardless of their providing network so that the convenience of network user and the flexibility can be improved simultaneously.
Also, in this aspect of the present invention, the notifying unit may notify the service information to a user agent of the second network, so as to notify the service information of one service providing device in response to a query from the user agent on behalf of said one service providing device.
In this case, it becomes possible for the user agent to obtain information regarding the services provided in the datalink layer protocol (such as the AV/C protocol of the IEEE 1394, etc., for example) with respect to the service location service in the protocol (the network layer protocol such as IP, etc., for example) by which it is operated. As a result, the user agent or the service location service can search out the services provided on the network regardless of their providing network so that the convenience of network user and the flexibility can be improved simultaneously.
Also, in this aspect of the present invention, the notifying unit may notify the service information by using a logical multiplex identifier defined by the communication control device and assigned to one service providing device as an access port for said one service providing device.
In this case, it becomes possible for the communication control device to recognize an access to the logical multiplex identifier as an access to the service provided by the service providing device, and carry out appropriate processing necessary for actually realizing that service. On the other hand, it becomes possible for the directory agent to use this logical multiplex identifier as an access point for the service of the service providing device in its response, so that it becomes possible to provide the uniform directory service regardless of the service providing network. Also, when this logical multiplex identifier is notified as the access point for the service of the service providing device, the user agent recognizes that this service is provided through this logical multiplex identifier regardless of the network, so that it becomes possible to provide the uniform service providing system by the network as a whole regardless of the network.
Also, in this aspect of the present invention, the communication control device may further comprises: a transfer unit for receiving a second protocol command in the second protocol which is destined to a port specified by the logical multiplex identifier assigned to said one service providing device, converting the second protocol command into a first protocol command in the first protocol, and transmitting the first protocol command to said one service providing device.
In this case, it becomes possible for the communication control device to recognize an access to the logical multiplex identifier as an access to the service provided by the service providing device, and send a command for service request to an entity which is actually providing that service after the command is converted into a form suitable for the protocol of the service providing datalink layer so that it becomes possible to realize the procedure of xe2x80x9cservice requestxe2x86x92service realizationxe2x80x9d as a whole. Also, the user agent recognizes that the access to the service of the service providing device is to be carried out in the layer in which that command is described so that it implies that accesses to various services on that network become possible as long as the simplification of processing, that is, the preparation of the environment for the service access in that layer, is made in advance, and therefore it is possible to provide significant contributions to the simplicity, efficiency, and uniformity of the service providing environment of that network.
Also, in this aspect of the present invention, the transfer unit may have a correspondence table for mapping second protocol commands in the second protocol into first protocol commands in the first protocol.
In this case, it becomes possible for the communication control device to carry out the command conversion in the case of an access to the logical multiplex identifier in a predetermined procedure. Consequently, it becomes possible for the communication control device to recognize an access to the logical multiplex identifier as an access to the service provided by the service providing device, and send a command for service request to an entity which is actually providing that service after the command is converted into a form suitable for the protocol of the service providing datalink layer so that it becomes possible to realize the procedure of xe2x80x9cservice requestxe2x86x92service realizationxe2x80x9d as a whole. Also, the user agent recognizes that the access to the service of the service providing device is to be carried out in the layer in which that command is described so that it implies that accesses to various services on that network become possible as long as the simplification of processing, that is, the preparation of the environment for the service access in that layer, is made in advance, and therefore it is possible to provide significant contributions to the simplicity, efficiency, and uniformity of the service providing environment of that network.
Also, in this aspect of the present invention, the notifying unit may notify the service information in a form of a home page for issuing a first protocol command in the first protocol for controlling a service provided by one service providing device, and the communication control device may further comprises: a receiving unit for receiving a message based on the home page from said device connected with the second network; and a control unit for controlling said one service providing device by the first protocol command issued according to said message received by the receiving unit.
In this case, it becomes possible for the user receiving and operating the home page to carry out the remote control even for the devices that interpret only the protocol depending on the link layer technique such as AV devices connected to the IEEE 1394, regardless of the protocol of the service providing device connected to the first network.
Also, in this aspect of the present invention, said message may contain a second protocol command in the second protocol which is depending on the second network for controlling the service provided by said one service providing device, and the control unit may convert the second protocol command contained in said message into the first protocol command by referring to a correspondence table of first protocol commands and second protocol commands.
In this case, when the specific second protocol command information (remote control command) is received through the receiving unit, what operation should be done to a desired device of the first network (the service providing device connected to the first network) can be ascertained by referring to the above described correspondence table.
Also, in this aspect of the present invention, said message may also contain an address depending on the second protocol and a multiplex identifier for identifying said one service providing device, and the control unit may also control said one service providing device as identified by said multiplex identifier in the first protocol command.
In this case, a node receiving the home page can specify the service providing device connected to the first network which is a control target as well as its desired operation by acting on an object referred through the hyperlink by using the second protocol command (remote control command), so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the home page may contain a program for generating a second protocol command in the second protocol for controlling the service provided by said one service providing device and said message may contain the second protocol command generated by said program.
In this case, a node receiving the home page can activate a program (e.g. JAVA program) set in correspondence to it so as to specify the service providing device connected to the first network which is a control target and issue a command for specifying its desired operation, so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the control unit may activate a program for issuing the first protocol command with respect to said message received by the receiving unit.
In this case, a node receiving the home page can activate a program (such as CGI script) set in correspondence to it so as to specify the service providing device connected to the first network which is a control target and issue a command for specifying its desired operation, so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the communication control device may further comprises: a home page creation unit for creating a home page for issuing a first protocol command in the first protocol for controlling a service provided by one service providing device according to the service information collected by the collecting unit, so that the notifying unit notifies the service information in a form of the home page created by the home page creation unit; a receiving unit for receiving a message based on the home page from said device connected with the second network; and a control unit for controlling said one service providing device by the first protocol command issued according to said message received by the receiving unit.
In this case, it becomes possible for the user receiving and operating the home page to carry out the remote control even for the devices that interpret only the protocol depending on the link layer technique such as AV devices connected to the IEEE 1394, regardless of the protocol of the service providing device connected to the first network.
Also, in this aspect of the present invention, the home page creation unit may have a table registering a second protocol command in the second protocol for controlling the service provided by said one service providing device that corresponds to the first protocol command which is prescribed for the service provided by said one service providing device, and the home page creation unit may create the home page by obtaining from said table an information regarding the second protocol command that corresponds to the service information collected by the collecting unit.
In this case, it becomes possible to display a list of remote control operations for the service providing device that can be realized by the second protocol command information (remote control commands). so that it becomes possible to create the home page that enumerates the operational remote control methods.
Also, in this aspect of the present invention, said message may contain a second protocol command in the second protocol for controlling the service provided by said one service providing device, and the control unit may convert the second protocol command contained in said message into the first protocol command by referring to a correspondence table of first protocol commands and second protocol commands.
In this case, when the specific second protocol command information (remote control command) is received through the receiving unit, what operation should be done to a desired device of the first network (the service providing device connected to the first network) can be ascertained by referring to the above described correspondence table.
Also, in this aspect of the present invention, said message also may contain an address depending on the second protocol and a multiplex identifier for identifying said one service providing device, and the control unit may control said one service providing device as identified by said multiplex identifier in the first protocol command.
In this case, a node receiving the home page can specify the service providing device connected to the first network which is a control target as well as its desired operation by acting on an object referred through the hyperlink by using the second protocol command (remote control command), so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the home page may contain a program for generating a second protocol command in the second protocol for controlling the service provided by said one service providing device and said message may contain the second protocol command generated by said program.
In this case, a node receiving the home page can activate a program (JAVA program) set in correspondence to it so as to specify the service providing device connected to the first network which is a control target and issue a command for specifying its desired operation, so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the control unit may activate a program for issuing the first protocol command with respect to said message received by the receiving unit.
In this case, a node receiving the home page can activate a program (such as CGI script) set in correspondence to it so as to specify the service providing device connected to the first network which is a control target and issue a command for specifying its desired operation, so that it becomes possible to carry out the remote control of the service providing device connected to a desired first network.
Also, in this aspect of the present invention, the communication control device may further comprises: a memory unit for assigning a second logical multiplex identifier to a service provided by one service providing device on the first network which is identified by a first logical multiplex identifier, and storing a correspondence between a set of a first address of said one service providing device and the first logical multiplex identifier and a set of a second address accessing from the second network and the second logical multiplex identifier, such that the notifying unit notifies the service information in order to present the service provided by said one service providing device as a service accessible from the second network at the second address and the second logical multiplex identifier; and a packet transfer unit for carrying out packet transfer between the first network and the second network in order to provide the service provided by said one service providing device to the second network according to the correspondence stored by the memory unit.
In this case, it becomes possible for the user on the second network to realize an access to the service provided on the first network even when the first protocol and the second protocol use different address systems, as in a case where the second protocol is operated by the IPv4 address system while the first protocol is operates by the IPv6 address system or by the private IP address system.
Namely, the services provided on the first network are presented to the second protocol as if they are provided by this communication control device, using the home page as a way of presentation to the user of the second network, for example. When there is an access to the service from the user of the second network, a packet used between the user of the second network and this communication control device is converted into a packet used between this communication control device and the service provided on the first network by using the correspondence (address and port number conversion table) stored in the memory unit, so that the user of the second network and the service provided on the first network recognize this communication control device as carrying out transparent packet exchanges.
Also, in this aspect of the present invention, the communication control device may further comprises: a unit for collecting first logical multiplex identifiers and first addresses of the service providing devices on the first network.
In this case, it becomes possible to automatically update the home page as a way of presentation, for example, according to the collected information regarding the service providing devices on the first network.
Also, in this aspect of the present invention, the communication control device may further comprises: a second memory unit for storing identifiers of packets transferrable to the first network; and an output unit for outputting those packets having identifiers which are stored by the second memory unit among packets entered from the second network.
In this case, it becomes possible to prevent improper packet intrusion into the first network from the external network such as the public network by carrying out the user authentication and the like in advance.
According to another aspect of the present invention, there is provided a communication device, comprising: an information memory unit for storing a configuration information which dynamically describes service information regarding services provided at said communication device; and a communication unit for carrying out a communication with a communication control device for recognizing the services of said communication device, by using the configuration information stored in the information memory unit.
In this aspect of the present invention, the other node communicating with this communication device can timely recognize applications serviced by this communication device at that point by making an access to the information memory unit, so that the directory service for network configuration and the detection of services of mobile nodes become possible and therefore the flexibility in the network operation can be improved. In particular, when the operating services change dynamically or the services are realized by software, the service operation state dynamically changes frequently due to the installment or the version upgrading of software, so that it is quite effective to change the service configuration information dynamically.
Also, in this aspect of the present invention, the configuration information may also describe attribute information regarding attributes of said communication device.
In this case, it becomes possible to notify both the service based configuration information and the device based configuration information to the other node communicating with this communication device, so that it is effective in simplifying the choice between the service specific configuration information or the device specific configuration information when the other node constructs the directory information of the network to which this communication device is connected. This is particularly effective in dealing with both users who are familiar with the service by service operation/search and users who are familiar with device by device operation/search.
Also, in this aspect of the present invention, said communication device may be connected to a network, through which the communication unit carries out the communication with the communication control device and at least one other network, and the configuration information may also describes at least a part of information regarding services provided at devices on said at least one other network.
In this case, the nodes other than said communication device which are connected to the first network can recognize the configuration information for the other network to which this communication device is connected. Consequently, it becomes possible to recognize the configuration information for all the inter-connected networks from the information memory unit through the communication unit of this communication device, so that it becomes possible to simply the mechanism and works required for the network management and the network service registration.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.